A film coating of DLC formed on a sliding surface of component parts of an engine or the like is normally formed using a CVD (chemical vapor deposition) film forming method because the surface smoothness as well as the deposition rate are higher in the CVD film forming method than those in the sputtering deposition method using PVD (physical vapor deposition method) which requires long a deposition time period, thereby enabling mass production and lowering manufacturing cost of the DLC coating layer.
Further, like a DLC film coating on a sliding component disclosed in a Patent Publication No. 1, metal such as Cr (chromium), Mo (molybdenum) and or like are added to DLC to form an Me-DLC layer (metal added DLC) which has low friction properties.